hi Joy,
Congratulations for your NEW HTC P3000 aka HTC Wave100. Have been using couple of devices since its launch & had faced a lot of issues, but thanks to this wonderful forum & helping members, i somehow, managed to solve many of them.
First of all, you need to Install Resco Explorer with Registry add-in to play with Wave100. Search the forum to get one..
1) Browse HKCU\control panel\sound categories\in call\ < set "initial volume" to 4 > then Soft Reset the phone.
2) Please refer for your 2016 issue.. Its a tested workaround in both my p3000s as well as in my mogul.. its a post by a very very respected guru of this forum "dkaile".
3) It is definately a problem, but you can always switch off your screen by pressing power button (on top of the device adjacent to SD card Slot), after making any call.., at least am doing the same, whenever am using it..
4) i am very much able to send as well as receive files through bluetooth.
5) have tested my nokia bh-100 handsfree with this, and it works fine..
your last two issues are related to bluetooth, please elaborate, ..